JP2606715B2 - Manufacturing method of organic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photoconductive layer on a support, in which an organic resin is provided on part or all of the photoconductive layer. The present invention relates to a method for manufacturing an organic photoreceptor which forms a photosensitive drum of an electrostatic copying machine, a laser printer or the like by being provided as a wear-resistant layer.

In addition, the present invention provides a plasma-enhanced plasma-enhanced (PCVD) method using a high-frequency or direct-current electric field at the same time, over a surface to be formed, particularly over a large area, at a high film growth rate, to form a carbon- or carbon-based film. The present invention relates to a method for producing an organic photoreceptor for forming an electrostatic copying machine or the like, on which is formed.

[Conventional technology]

Conventionally, as a thin film forming technique by a gas phase reaction used for manufacturing a photoreceptor of a long-life electrostatic copying machine, a plasma using a high-frequency or DC electric field using a silicide reactive gas is used.
A method using an amorphous silicon film as a photoconductor by a CVD method (glow discharge CVD method) is known.

However, a photoreceptor such as an electrostatic copying machine is formed with an amorphous silicon film using the above-described glow discharge CVD method. Since the film thickness of the photoreceptor needs to be about 5 μm, cracks are likely to occur in the photoreceptor. In addition, irregularities are likely to be formed on the surface of the photoconductor. Further, the flakes attached to the inner wall of the reaction vessel during the manufacturing process have a defect that the flakes fall on the surface on which the photoreceptor is formed, and voids and pinholes are easily formed.

For this reason, the amorphous silicon film is hardly used as a photoreceptor and has a long service life, but is only one step in practical use.

On the other hand, as a photosensitive member, an electrostatic drum using an organic resin is known. This drum is characterized by being industrially inexpensive and easy to mass-produce, since it only coats the organic resin on the support. However, its life is limited to 50,000 to 70,000 sheets of electrostatic capacity, and it is deteriorated and cannot be used.

For this reason, if the photoreceptor itself is made of an inexpensive organic resin, it has been required that the photoreceptor be overcoated with a highly hard and slippery insulating film as a wear-resistant layer thereon. And the upper surface of the photoreceptor has a flat surface,
In addition, since the substrate is made of an organic resin, there has been a demand for a method of forming a drum for an electrostatic copying machine by means that enables formation at -100 ° C. to + 200 ° C. in principle.

For this purpose, “Plastics coated with a carbon film” filed by the present applicant (February 10, 1987)
There is Japanese Patent Application No. 62-28957 (Japanese Patent Application No. 6-76666).

Further, for example, a semi-amorphous semiconductor disclosed in JP-A-57-68017 is described about its microcrystalline structure.

 Another conventional example is as follows.

JP-A-61-183663 describes a method for producing a photosensitive material having an overcoat layer, in which a diamond-like overcoat layer is formed by a plasma CVD method as a surface protective layer of a photosensitive member.

Japanese Patent Application Laid-Open No. 61-255352 describes that a photoreceptor is provided with an ionizing electrode and thermionic radiation in the vicinity of a carbon evaporation source, accelerates ionized carbon by a DC electric field, and causes the carbon to adhere to the surface of the photoreceptor. ing.

Japanese Patent Application Laid-Open No. 61-264355 discloses an electrophotographic photoreceptor in which a carbon film or the like in which diamond crystal grains are scattered is formed on the surface of the electrophotographic photoreceptor at low temperature and low pressure using plasma or ions. Have been described.

JP 62-9355 describes an amorphous carbon-containing electrophotographic imaging member which describes a photosensitive imaging member comprising hydrogenated amorphous carbon having a band gap of about 0.5 to about 5 electron volts. I have.

[Problems to be solved by the invention]

The abrasion-resistant overcoat layer formed on the surface of the photoreceptor must have a large surface area without irregularities and have a high hardness film adhered to the surface of a hot and weak photoreceptor made of resin.

However, the plasma CVD method used for forming a carbon film disclosed in Japanese Patent Application Laid-Open No. 61-264355 has a disadvantage that the film growth rate is low when formed at a low temperature.

Therefore, it is general to apply heat to the above-described conventional film forming method using the plasma CVD method or the photo CVD method.

In addition, the plasma CVD method and the photo CVD method in the above-mentioned conventional example have a disadvantage that a product adhering to the wall of the reaction space falls and forms irregularities on the coating film surface.

The present invention has been made to solve the above problems, and provides a method for producing an organic photoreceptor in which a film containing carbon or carbon as a main component is formed without heating a support of the film in a reaction space. The purpose is to do.

An object of the present invention is to provide a method for producing an organic photoreceptor having a large surface area without unevenness without causing a product attached to a wall of a reaction space to fall while a film is formed on the surface of the photoreceptor. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing an organic photoreceptor which promotes the decomposition and activation of a reactive gas composed of a carbonized material at a low temperature to accelerate the film formation rate.

[Means for solving the problem]

In order to achieve the above object, a method for producing an organic photoreceptor according to the present invention comprises the steps of: providing a surface of an organic photoconductive material provided as a photoconductive layer on a conductive support (10); An organic photoreceptor having a coating containing, as a main component, a reaction space (1) for exciting a source gas and a carrier gas while simultaneously supplying a source gas of a hydrocarbon and a carrier gas such as hydrogen. )), While applying a high-frequency electric field to the electrodes (20, 20 ') held therein, and simultaneously applying a positive DC bias to the conductive support (10) as a base, and removing carbon or carbon at room temperature or while cooling. It is characterized by forming a coating as a main component.

[Action]

The present applicant applies a high-frequency electric field to the electrode held in the reaction space and applies a positive DC bias to the conductive support, thereby heating the conductive support and heating the carbon or carbon at room temperature without heating the conductive support. It was discovered that a coating as a main component was produced.

At the same time, the present applicant has discovered that the method for producing the above-mentioned coating improves the adhesion to the organic photoreceptor and provides a conductive support having high hardness over a large area and having no unevenness.

Thus, the present invention provides an organic photoconductive material overcoated on a support by a coating method or another method, and further, if necessary, a barrier layer is formed thereon, which is excellent in smoothness and abrasion resistance. An excellent insulating carbon or a coating containing carbon as a main component could be overcoated.

As a result, the present invention provides a conventional amorphous silicon drum having abrasion resistance, but with severe surface irregularities,
The disadvantage that cracks easily occur was eliminated.

On the other hand, in the present invention, the carbon film having abrasion resistance can be formed by forming an organic resin as a base on an organic photoconductive material or an organic resin blocking layer on the organic photoconductive material at room temperature or while cooling. However, since the same main component carbon as that of the organic resin is used, they adhere to each other well.

Furthermore, the carbon film of the present invention has a high Vickers hardness of, for example, 2000 kg / mm ² or more, and has good wear resistance. Providing a carbon film as a blocking layer on a photosensitive drum using the photosensitive organic resin of the present invention is an excellent one having an extremely large synergistic effect.

In the present invention, since a reactive gas is previously excited by microwaves and high-frequency plasma is used, this carbon film can be formed into a carbon film in which the same bond as diamond or a diamond is partially mixed.

In addition, the microwave excitation of the present invention simultaneously introduces hydrogen, an inert gas or a non-reactive gas (a gas that produces only a gas even when decomposed or reacted) and a hydrocarbon gas into the resonance space at the same time. It is activated. At this time, this carbon film was preferable because the product hardly adhered to the inner wall surface thereof in the presence of a magnetic field.

 Hereinafter, the present invention will be described with reference to Examples.

〔Example〕

Example 1 This example shows the production of a photoconductor by a plasma CVD method for producing a carbon film.

FIG. 1 shows a plasma CVD apparatus for producing a carbon film used in the present invention.

In Fig. 1, a stainless steel container (1 ') has a lid (1 ") and constitutes a reaction space (1). This container (1') has an organic photoconductive material or an organic photoconductive material in advance. A substrate (10) coated with a barrier layer of an organic resin on a support was disposed on the substrate, and the substrate (10) was held while being rotated by holders (8) and (8 '). On the 1 ″) side,
A homogenizer (20 ') is provided for the exhaust port (7). When mounting the base (10), the lid (1 ") is opened upward. A high-frequency voltage or a DC voltage is applied between one electrode (20 ') and the other mesh electrode (20). Is done.

Here, 13.56 MHz or a high-frequency electric field with a DC bias is applied from a high-frequency or DC power supply (6). The substrate (10) is positioned so as to be perpendicular to this electric field. The base (10) is rotated in the circumferential direction.

In FIG. 1, when the left-right direction is long, the drum-shaped substrate (10) may be moved while rotating at the same time as the film formation. A large number of the substrates (10) may be provided (in the front-rear direction in the drawing), and these may be moved while rotating to produce a large number of uniform thicknesses simultaneously.

The reactive gas is supplied from the doving system (13) through (18) to the resonance space (2) using microwaves formed in the quartz tube (29). In the resonance space (2), air-core magnet coils (5) and (5 ') are arranged outside to apply a magnetic field.

At the same time, for example, a microwave of 2.45 GHz is supplied to the resonance space (2) via the analyzer (4) by the microwave oscillator (3). In the resonance space (2), methane is added from (32) as a reactive gas in order to cause Whistler mode resonance.

Further, diborane (B ₂ H ₆ ) or phosphine (PH ₃ ) diluted with hydrogen is added from (32), and a hydrogen carrier gas is added from (31). For example, methane: hydrogen =
The ratio was set to 1: 1, and a plasma electric field to which 50 W to 1 KW was applied as high frequency power was set to 0.03 W / cm ² to 3 W / cm ² . DC bias has a large amount of hydrogen in the carbon film unless added.
An optical energy bandwidth of 2.5 eV to 3.5 eV is obtained. If the base (10) side is a positive bias, the hydrogen ions are repelled and the hydrogen content in the film is reduced as a result, and the optical energy bandwidth becomes 1.0 eV to 2.0 eV.

The surface temperature of the substrate (10) is -100 ° C to + 200 ° C, preferably -100 ° C to + 150 ° C. Since the heat resistance of the organic photoconductive material or the organic material is not sufficiently high, there is no damage during the coating of the carbon film. , Melting, and alteration.

Further, by performing preliminary excitation with microwaves, the film formation rate in this case can be 500Å / min to 1000Å / min.
Very high-speed film formation was possible.

However, without this preliminary excitation, a film formation rate of only 100 ° / min to 200 ° / min could be obtained.

Thus, the carbon film is 0.1 μm to 4 μm, preferably
The layer was formed to a thickness of 0.5 μm to 2 μm, and its optical energy bandwidth was widened as a layer. As a result, it acted as both a wear-resistant layer and a barrier layer for electrostatic charges. However, the Vickers hardness of the carbon film is 4000 kg / mm ²
In addition, since it is lowered to 2000 kg / mm ² or 4000 kg / mm ^2, it is necessary to optimally design the energy band, hardness, and thickness for practical use.

In the present invention, a carbon film having a Vickers hardness of 2,000 kg / mm ² or more and a thermal conductivity of 2.5 W / cm deg or more is designed to be capable of copying 200,000 sheets or more in a practical use life. Of course, the 2,000 Kg / mm ² to the hardness of 1000 Kg / mm ² without,
The product life is reduced to 100,000 or 200,000 sheets. With such a product life, commercialization is still possible if a reasonable market is sought.

The pressure in the reaction space of this example was adjusted by adjusting the exhaust amount of a vacuum pump (9) using a turbo molecular pump together with a control valve (14) of an exhaust system (11).

Further, if necessary, in FIG. 1, in order to sufficiently spread the electron or the resonance-excited argon into the reaction space,
One electrode (20) is a reactive gas homogenizer (20 ')
Can be used in combination. That is, the gas (21) released from the holes of the homogenizer (20 ')
A film is uniformly formed over a large area on the surface, and the thickness thereof is preferable because uniformity over a large area can be obtained more favorably.

Of course, if the homogenizer (20 ') is placed in the reaction space, collisions of electrons and active gas on this surface are inevitable, resulting in increased energy consumption and a reduced growth rate. Therefore, in order to obtain a higher growth rate in the entire space, microwave excitation was more effective than plasma CVD alone.

Experimental Example 1 In this experimental example, hydrogen and methane were used at a ratio of 1: 1, and an amorphous carbon film containing diamond bonds or an amorphous carbon film containing diamond microcrystals was formed.

The pressure in the reaction space is 0.1 torr,
Hydrogen was supplied at 200 SCCM from 1). In addition, methane was supplied from (32) at 200 SCCM. Microwave is 2.45GHz
With a frequency of 30W to 1.3KW, for example 500W
Was adjusted. The resonance intensity of the magnetic fields (5) and (5 ') is 875
Gaussian. A 13.56 MHz high frequency current of 500 W was applied. After starting the discharge, the exhaust system was adjusted.

Cylindrical substrate (10) having a conductive surface at least partially (state in which organic photoconductive material is formed on a support)
Was used to form a non-single-crystal carbon film, for example, an amorphous carbon film. And unnecessary gas was discharged | emitted by the exhaust system (11) through the exhaust port (7). Then, at a substrate (10) temperature of room temperature (about 150 ° C. by actual heating by plasma), a film formation rate of 30 ° / sec was able to be formed, and the film formation time was about 15 minutes. This speed is 20 times faster than 1.5Å / sec obtained by plasma CVD alone. Examination of one example of the electrical characteristics of this amorphous carbon revealed that the amorphous carbon had a specific resistance of 10 ¹⁰ Ωcm, a Vickers hardness of 2300 Kg / mm ² , and an optical energy band width of 1.8 eV.

If the reactive gas is not methane but a mixed gas of ethylene or acetylene and hydrogen, a further improvement in the film growth rate can be expected.

Example 2 A photosensitive drum of a copying machine using this apparatus was manufactured.
As the substrate (10), aluminum or an alloy thereof having a diameter of 25 cm and a length of 30 cm was used as a support. An organic photoconductive material coated thereon was used. The substrate (10) was set in the apparatus shown in FIG.
Orr and 20 SCCM of hydrogen were introduced from (31), and 200 SCCM of CH ₄ were introduced from (32). The gas was at room temperature and was not heated or cooled. After this, a plasma discharge power supply (13.56 MHz output 300
W, DC bias +200 V is applied to the gas) to form 200 ° / min in this embodiment.

 Thus, a carbon film having a thickness of 0.4 μm was formed.

Thereafter, the reaction chamber was evacuated once, and the residual gas was evacuated outside the reaction chamber.

Example 3 A photoreceptor similar to that of Example 2 was manufactured using a whistler mode and high-frequency plasma CVD.

The fabrication conditions are the same as in Example 1. The substrate (10)
After cooling to −30 ° C., +400 V was applied to the DC bias.
Then, a carbon film as thick as 0.5 μm was formed. In this example, the film was formed while rotating the base (10) and moving it back and forth and right and left.

Room temperature → 150
Table 1 shows the results of 100 temperature cycles from ° C to room temperature. The coating did not crack, peeled off or peeled off the substrate, and the yield was about 100%.

In addition, the sample of this embodiment is mounted on an electrostatic copying machine, and a metal which is in close contact with the photosensitive drum to prevent the transfer paper from being spread.
Alternatively, a squeegee with a carbon film overcoated thereon was provided, but the carbon film of the photoreceptor was made of an organic photoconductive material.
Also a metal support, without organic photoconductive material may peel off, did not change with respect to 10 ^five to 10 ^six copying operation in the A4 size.

This means that if there is no coat of this carbon film, 10
Compared to that with only up to ^four to 7 × 10 ⁴ sheets,
It is equivalent to having infinite wear resistance.

〔The invention's effect〕

In the present invention, a high-frequency electric field is applied to an electrode held in a reaction space, and a carbon or carbon-based film is overcoated on an organic photoreceptor while a positive DC bias is applied to a conductive support. It was done. And
The high-frequency electric field applied to the electrodes and the DC bias applied to the conductive support as described above produce, for the first time at room temperature, a coating with good adhesion and high hardness without unevenness on the surface of the organic photoreceptor. We were able to.

[Brief description of the drawings]

FIG. 1 shows a plasma CVD apparatus for producing a carbon film used in the present invention. DESCRIPTION OF SYMBOLS 1 ... Reaction space 2 ... Resonance space 3 ... Microwave oscillator 4 ... Analyzer 5 ... Air-core magnet coil 6 ... Power supply 7 ... Exhaust port 8, 8 '... Holder 9 ... Vacuum pump 10 ... ... Substrate 11 ... Exhaust system 13 ... Doping system 20, 20 '... Reticulated electrode (homogenizer)

Claims (1)

(57) [Claims] 1. A method for producing an organic photoreceptor having a wear-resistant layer of carbon or carbon as a main component on a surface of an organic photoconductive material provided as a photoconductive layer on a conductive support. While simultaneously supplying a hydride source gas and a carrier gas such as hydrogen, a high-frequency electric field is applied to an electrode held in a reaction space to excite the source gas and the carrier gas, and at the same time, the conductive A method for producing an organic photoreceptor, comprising forming a coating containing carbon or carbon as a main component while applying a positive direct current bias to a porous support and at room temperature or while cooling.